Hadden is in upbeat mood

The Wallabies have not tasted defeat to Scotland in 15 matches, but Hadden says that run can be ended on Saturday.

"We have got to the stage where I believe we have a genuine opportunity to take a famous scalp in the build-up to the World Cup," he said.

"It is going to be a massive task but we have narrowed the gap between the southern and northern hemisphere."

Interview: Scotland captain Chris Paterson

The closest Scotland have got to the Wallabies since a famous win in Brisbane in 1982 was a 29-19 defeat at Murrayfield in 1996.

"Australia are possibly the side which has embarrassed us most in recent times," Hadden recalled.

RECENT METINGS Nov 04: Scot 17-31 Aus Nov 04: Scot 14-31 Aus Jun 04: Aus 34-13 Scot Jun 04: Aus 35-15 Scot Oct 03 (WC): Aus 33-16 Scot Nov 00: Scot 9-30 Aus

"Since we last beat them, they have only failed to score over 30 points against us twice, and, on those occasions they scored 27 points in 1992 and 29 points in 1996.

"So there has been a really long sequence of embarrassing defeats."

Hadden is encouraged though by the "steady progress" Scotland have made this year, with a run of five consecutive wins at Murrayfield.

"We are a lot tougher to beat than we used to be," he said, while dismissing the significance of Ireland's emphatic 21-6 defeat of the tourists last Sunday.

Callam will aim to help Scotland to a win at Murrayfield

"In my opinion, the Irish are the best side in the northern hemisphere at the moment, and I think that was borne out on Sunday," Hadden said.

"We probably don't have the capacity to play the way which Ireland play, so it will probably be a very different game this week."

Hadden has made two changes following last weekend's victory over the Pacific Islanders in the second autumn Test.

Callam replaces the injured Johnnie Beattie at number eight and Mike Blair starts at scrum-half in place of the injured Chris Cusiter, while there is more youth on the bench with Rory Lawson and Kelly Brown.

"We are aware we haven't got the deepest pool of players in the world, and have to select a squad of 30 for the World Cup, which is less than 10 games away now," Hadden added.

"So we are looking to give people the opportunity to cement their position or put their hand up and claim a place in the squad."